Magnetic chuck



Patented Jan. 20, 1,925.

UNITED STATES A y 1,523,711 PATENT oFElcE.

BENT M. w. H ANsoN, or HARTFORD, CONNECTICUT.

y MAGNETIC CHUCK.

riginal application led `Iin'ch 31. 1921, Serial No. 457,338. Divided andthis application led April '27, 1922. serial No. 556,824.

To all whom 'it may concern.'

Be it known that I, BENGT M.- W. HAN- soN, a citizen of the United States, and resident ofHartford, county of Hartford, State of Connecticut,have invented certain new and useful Improvements in a Magnetic Chuck, of which the following is a specication.

The object of the present invention is to produce a magneticI chuck having various features of novelty and advantage. It is especially designed to provide a chuck, the active face of which shall be iliade up of a plurality of sections, each of which may be separately magnetiaed and the magnetic effects separately cont-rolled. The embodiment of the invention selected for illustration and description .is of a rotary spindle withy parts constituting the magnetic chuck built directly into the end of the spindle, and the disclosure of thev invention will be based upon this embodiment. It is to be understood however, that the present disclosure is way of exempliiication only, it being evident that the invention as set forth in the appended claims is susceptible of use in various other arrangements, adaptations and is capable of modification and changes.

In the" drawing: f

Fig. 1 is a central vertical section of a chuck made in accordance with my invention, and

Fig. 2 is a front end view thereof.

Referring to the drawing, a is a bearing and b is a chuck rotatably mounted therein and driven from some suitable source of power, as through the gear c. The end of the spindle constitutes a chuck face and, as here shown, is made up of two parts, an outer section 2, with a central recess within which is fitted a central chuck block 6, which constitutes the inner or central section of the chuck face. This block is removably positioned within the'central recess and may be held in place as by means of the screw bolt 7. v

l0 designates a magnetizing coil ittinor into the central chuck block and connected by the contact members 11 with the circuit wires leadin to the contacts l2, 12 at. the rear end o the spindle which are provided with brushes 13, 13 in the circuit of one of which a resistance 14 is located in order that the strength of the magnetic force in the chuck block 6 can be varied for purposes which will hereinafter be descri ed. This circuit 'is controlled by a proper switch l5 in order that the current can be delivered to the coil 10 either directly or through tlu` resistance 14. 20 designates a n'iagnetizing coil in the outer section 2 of the chuck face and connected by circuit wires with contact rin s 2l, 21 and brushes 22, 22, equipped wlth a proper switch 23 for controlling the current supply to the coil 20. f

It will be seen from this description that the chuck face comprises two sections insulated from one another; that each section may be separately magnetized, and that in one of the sections, as the central one here illustrated, the magnetic effect may be varied.

In operation, the piece of work, the size and configuration of which are immaterial, is positioned against the chuck face and a light current is thrown into the coil l0 of the central chuck block 6 to produce sui cient magnetism to hold the piece in place but permitting it to be shifted until it is precisely centered relative to the spindle. lhen by further action of the switch 15 the resistance is cut out, delivering more current to the coil and conse uently obtaining greater magnetic effect to(l1 position. 4After the work is thus positioned, the switch 23 is operated to throw the current into the coil 2O in the outer chuck section 2, producing a very heavy magnetic effect which operates over the large area of the work which lies against the end of the outer chuck section 2, thus securely holding the work against movement when the pressure ofthe tool is applied.

It will be seen from the foregoing that the work is directly held by the magneticy effect in the central magnet-ic chuck block 6, and at first is lightly held in order that it may be ycentered properly with relation to the spindle, after which the full current is turned into the coil 10 and into the coil 20, so that the work is held with security. It is, of course, evident that the chuck may or may not be provided with holding plates positioned against the chuck face of the outer section 2 so as to be held by the magnetic effect of this section, these holding plates being adjustable when the current is turned off so as to bring them into proper engagement with the work. Such an arrangement is shown and described in my old the piece in ending application S. No. 457,338, led arch 31, 1921, of which the present application is a division. In the present inf stance, the` piece'of Work w', illustrated in dotted lines, is shown asbeingl in the form of a centrally apertured disc of such size as to overlie the faces of'lboth of the chuck sec' or both of them may be performed simultaneously at one and the same setting of the VWork, thus insuring concentricity of the surfaces operated upon. The central chuck block is recessed as at 9, so that the tool z may be run through the opening in the Work Without being brought into contact With the chuck block. Y A number of chuck blocks 6, having diii'erent sized recesses, maybe pro- .vided so that, as the bores in 'the various pieces of Work vary from one another, re-

- means surrounding' said sectlon and coopcesses `of different. sizes can be provided..

It is, of course, obvious'that my invention is susceptible of various modifications and changes .which are Withinthe spirit of the invention-Without departing from the scope of the yfollowing claims, it being understood that the present disclosure ofmy invention to be taken as restrictive of my conception. I claim asmy invention: y y

1. In a device ofthe character described, a chuck face comprising a plurality 'of sections insulated from one another and separate means for separately and' independ# entl)7 magnetizing said sections.

2. In a device of the character described,

a chuck face comp-rising a plurality ofv secof-two sections, one positioned within and magnetically insulated rfrom the other, a magnetizing coil associated with each section, independent means associated with each coil for controlling a flow of current therethrough, and means associated with the said coil of the inner section for varying the intensity ofthe magnetic effects therein.

4. In a'chuck, a magnetic section adapted to directlyv hold apiece of Work by the magnetic effects Within said section, means for varying the magnetic effects within said section, and means spaced from said section and co-operating Work in position." c v 5. A rotary chuck having' a centrally 1ocated. section, means for magnetizing the same, means for varying the intensity of therewith for holding the the magnetic effects within said lsection, and

'6.' A rotaryv magnetic' chuck comprising a.

pair-of sections onev Wit-hin the other and lmeans forindependently andVV separately Y :magnetizing said sections. l f is by Way of illustration onlyand it is not BENGT M. HANso-N. 

